Medical research

Engineered miniature kidneys come of age

In recent years, researchers have created mini-organs known as organoids in the culture dish that contain many of the cell types and complex microarchitectures found in human organs, such as the kidney, liver, intestine, ...

Cancer

Treatment to a T? Taking a 'BiTE' out of lung cancer

Immune cells called T cells are key components in the fight against cancer. However, they sometimes struggle to recognize cancerous cells or to launch an appropriate response against them. T cell activity can be tweaked to ...

Neuroscience

New MRI sensor can image activity deep within the brain

Calcium is a critical signaling molecule for most cells, and it is especially important in neurons. Imaging calcium in brain cells can reveal how neurons communicate with each other; however, current imaging techniques can ...

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Cell (biology)

The cell is the structural and functional unit of all known living organisms. It is the smallest unit of an organism that is classified as living, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular (consist of a single cell). Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion or 1014 cells; a typical cell size is 10 µm; a typical cell mass is 1 nanogram.) The largest known cell is an unfertilized ostrich egg cell.

In 1835 before the final cell theory was developed, a Czech Jan Evangelista Purkyně observed small "granules" while looking at the plant tissue through a microscope. The cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells. All cells come from preexisting cells. Vital functions of an organism occur within cells, and all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.

The word cell comes from the Latin cellula, meaning, a small room. The descriptive name for the smallest living biological structure was chosen by Robert Hooke in a book he published in 1665 when he compared the cork cells he saw through his microscope to the small rooms monks lived in.

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